Immortal Bad Batch 2

During the final round of GAC I used Darth Bane against the new batch batch squad and fully killed 3/5 but then with only wrecker and omega left I used essence of dominance to siphon max health down to 1 which made them unkillable (never entered captured state or died) regardless of the damage dealt, and further siphoning their health didn't do it either. I can't find anything in their kit or the datacron that would make this interaction intentional.